Patent GB-651058-A (GB)
Title: Improvements in or relating to photographic processing apparatus
IPC: G03D5/00
Filed: 1948-09-14
Abstract: 651,058. Photographic processing apparatus. KODAK, Ltd. (Eastman Kodak Co., Tuttle, C. M., and Klauss, R. E.). Sept. 14, 1948, No. 24150. [Classes 98 (i) and 98 (ii)] [Also in Group XL (c)] Apparatus for processing an exposed lightsensitive film comprises a processing drum having a recess in the periphery thereof corresponding in area to an exposed frame of film to be processed, means for holding the emulsion surface of the exposed frame of film in covering relation with the recess, and means for supplying processing fluids to one end of the recess and withdrawing them from the other end thereof such that the fluids traverse the emulsion surface of the exposed frame. As shown in Fig. 1, the film F passes from a supply reel on the spindle 11 to a camera gate 14 where it records the image on the cathode-ray tube screen of a radar installation through a right-angled prism 18 and camera objective 17. The camera has a pivoted shutter controlled by a mechanism operating in timed relation with the film advancing mechanism and a driving mechanism for the radar aerial so that the shutter intercepts the light beam when the film is advancing and permits its passage when the film is stationary and during the time it takes the radar aerial to make one complete revolution. The film then passes round a processing sprocket 20, through a projection gate 23 where it is projected on to a screen, round a feed sprocket 31, and then to a take-up reel 33 also mounted on the spindle 11. The processing sprocket 20, the tension sprocket 24, and the feed sprocket 31 are driven at the same speed by the chain 37. As shown in Figs. 6 and 7, the processing sprocket 20 comprises a hollow drum 50 having teeth 51 for engaging the film perforations and making a lapped fit with a spindle 53, the drum 50 and spindle 53 being secured together by a screw knob 54. In an aperture 52 in the drum 50 is an insert 55 backed by a spacer 56 engaging the spindle 53, the insert 55 having a recess 34 having an area corresponding to the exposed area of the film. The upper end of the recess 34 connects with a channel 58 between the drum 50 and spindle 53 which is connected with the feed lines 59, 60 and 61 for developer solution, fixing solution, and air under pressure, and the lower end of the recess 34 communicates with an exhaust line 62 connected to a sump tank 63. When the sprocket 20 is in processing position, the feed lines 59, 60 and 61 are in alignment with the feed lines 591, 601 and 61<SP>1</SP> passing through the metal block 66, 67 and 68 heated by the electric heaters 69 controlled by a thermostatic switch 69<SP>1</SP>. Each of the three feed lines contains a spring-actuated poppet valve 72 engaging a cam 75 on the camshaft 76 driven through reduction gearing 77 from the processing motor Mp. Each of the feed lines contains an interchangeable restricted orifice 88 including a strainer, and the feed lines 591 and 60<SP>1</SP> are connected through strainers 83 to the developer and fixer tanks 70 and 71 provided with floats for indicating the height of the liquid and with valves 84 for drainage into the sump tank 63, also containing a float 87. The tanks 70 and 71 are maintained at atmospheric pressure by vents 82. During operation, the tank 63 is maintained under vacuum, so that liquid is only drawn through the feed lines and the recess 34 on opening of the appropriate valve 72 if a film F is positioned over the recess 34. The liquids could, however, be fed by pressure. A trough 89 is provided below the sprocket 20 to catch solution leaking between the film F and the aperture 34. The feed line 61<SP>1</SP> is connected to a source of compressed air. The valves 72 are arranged to open to supply (a) developer to the recess 34; (b) fixing solution ; (c) developer (to replace washing water), and (d) compressed air to dry the film.